scholarly journals Dose-dependent response of plasma ghrelin and growth hormone concentrations to bovine ghrelin in Holstein heifers

2006 ◽  
Vol 189 (3) ◽  
pp. 655-664 ◽  
Author(s):  
Hnin ThidarMyint ◽  
Hiroko Yoshida ◽  
Tetsuya Ito ◽  
Hideto Kuwayama
Keyword(s):  
Growth Hormone ◽  
Energy Homeostasis ◽  
Biological Activities ◽  
Control Group ◽  
Dependent Manner ◽  
Endocrine Activity ◽  
Gh Secretion ◽  
Total Ghrelin ◽  
Acyl Ghrelin ◽  
Dose Dependent

The stimulatory effect of the novel gastric-derived hormone, ghrelin, on growth hormone (GH) secretion has been reported in domestic animals as well as in humans and rats. The octanoyl modification on the Ser3 residue of ghrelin appears to be essential for its endocrine activity. A major portion of circulatory ghrelin lacks acylation but possesses some biological activities other than GH stimulation; therefore, both types of acylated and des-acyl ghrelin are supposed to be important for energy homeostasis. The effects of pharmacological doses of rat and/or human ghrelin on GH secretion have been reported recently in ruminants; however, the physiological effect of exogenous bovine ghrelin on its own plasma level and on GH secretion is still unknown. Moreover, the RIA systems for the measurement of bovine active ghrelin and for bovine total ghrelin including acylated ghrelin, des-acyl ghrelin and all ghrelin peptides with an intact bovine C-terminal have not yet been validated. In this study, we established the RIA system for bovine ghrelin, and the dose-dependent effects of synthesized acylated bovine ghrelin(1–27) on plasma active and total ghrelin, GH, insulin and metabolites were measured in Holstein heifers. Six animals were intravenously injected with synthesized acylated bovine ghrelin (0, 0.1, 0.5, 1.0, 5.0, 10.0 μg/kg body weight (BW)) and plasma hormone concentrations were measured from serially collected samples. Bovine ghrelin RIA showed that the basal level of total ghrelin is approximately 16 times higher than that of active ghrelin in bovine plasma. Both forms of ghrelin were increased in a dose-dependent manner in response to bovine ghrelin injections, peak values were reached at 5 min after administration and returned to pre-injected values within 15 min. Plasma GH was responsive to all doses of bovine ghrelin in a dose-dependent manner, peaked as early as at 5–10 min after injection and returned to the basal value within 60 min. The GH area under curve 1 h after injection of the smallest dose of ghrelin used in this experiment (0.1 μg/kg BW) was significantly higher than that of the vehicle (0.1% BSA saline)-injected control group (P<0.05). The GH response to the highest dose of ghrelin (10.0 μg/kg BW) was greater than the response to 5.0 μg/kg BW ghrelin (P<0.001). Plasma glucose concentrations were not significantly altered by the administration of bovine ghrelin while plasma insulin levels were transiently stimulated by the higher doses of ghrelin (1.0, 5.0, 10.0 μg/kg BW). Plasma non-esterified fatty acid levels also increased following ghrelin administration. Our study indicates that a considerable quantity of both acylated and des-acyl ghrelin is circulating in the bloodstream, and also confirms that ghrelin is not only a potent stimulator of GH secretion but also plays a considerable role in energy homeostasis in Holstein heifers.

Post-somatostatin rebound secretion of growth hormone is dependent on growth hormone-releasing factor in unrestrained female rats

1989 ◽  
Vol 122 (2) ◽  
pp. 583-591 ◽  
Author(s):  
H. Sugihara ◽  
S. Minami ◽  
I. Wakabayashi
Keyword(s):  
Growth Hormone ◽  
Adult Female ◽  
Wistar Rats ◽  
Bolus Injection ◽  
Female Rats ◽  
Dependent Manner ◽  
Gh Secretion ◽  
Female Wistar Rats ◽  
Plasma Gh ◽  
Dose Dependent

ABSTRACT To examine the characteristics of GH secretion following the termination of the infusion of somatostatin, unrestrained adult female Wistar rats were subjected to repeated infusions of somatostatin separated by 30-min control periods. When somatostatin was infused for 150 min at a dose of 3, 30 or 300 μg/kg body wt per h, the magnitude of the rebound GH secretion increased in a dose-dependent manner. The infusion of somatostatin at a dose of 300 μg/kg body wt per h for 60, 150 or 240 min progressively augmented the size of the rebound GH secretion. When an antiserum to rat GH-releasing factor (GRF) was injected i.v. 10 min before the end of the infusion, the peak amplitude of the rebound GH secretion (300 μg/kg body wt, 150 min) was reduced to less than 20% of that of control rats. The rebound GH secretion (300 μg/kg body wt per h, 150 min) was augmented by a bolus injection of human GRF (1 μg/kg body wt). The combined effect of the end of infusion of somatostatin and a bolus injection of GRF on the amount of GH secreted was additive. The plasma GH response to GRF was completely inhibited when human GRF (3 μg/kg body wt per h) and somatostatin (300 μg/kg body wt per h) were infused simultaneously for 150 min. The magnitude of the rebound GH secretion following the termination of the co-administration was larger than that following the somatostatin infusion alone, but this rebound was not enhanced by a bolus injection of human GRF. Moreover, the amount of GH secreted was significantly less than that after the termination of somatostatin infusion plus a bolus injection of human GRF in the absence of preceding GRF administration. These results suggest that at least part of the influence of somatostatin on GH secretion is exerted at the level of the hypothalamus through modulating the release of GRF. In addition, it is inferred that the simultaneous infusion of GRF and somatostatin induces the attenuation of the GH response to GRF through a receptor effect. Journal of Endocrinology (1989) 122, 583–591

Inhibition of L-692,429-stimulated rat growth hormone release by a weak substance P antagonist: L-756,867

1997 ◽  
Vol 152 (1) ◽  
pp. 155-158 ◽  
Author(s):  
K Cheng ◽  
L Wei ◽  
L-Y Chaung ◽  
W W-S Chan ◽  
B Butler ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Substance P ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Gh Secretion ◽  
Substance P Antagonist ◽  
The Right ◽  
Dose Dependent

Abstract H2N,d-Arg,Pro,Lys,Pro,d-Phe,Gln,d-Trp,Phe,d-Trp,Leu, Leu,NH2 (L-756,867), a weak substance P antagonist, inhibited L-692,429-stimulated GH release from rat primary pituitary cells in a dose-dependent manner. At a concentration of 50 nm, L-756,867 shifted the dose–response curve of L-692,429-induced GH release to the right by about tenfold. It also impaired the ability of L-692,429 to potentiate the effect of growth hormone-releasing factor (GRF) on GH release. Substance P (1 μm) had no effect on basal or L-692,429-stimulated GH release. When tested in anesthetized rats, L-756,867 inhibited L-692,429- and growth hormone-releasing hexapeptide- (GHRP-6)-stimulated GH secretion in a dose-dependent manner. Complete inhibition was observed at an i.v. dose of 100 μg/kg of L-756,867. However, at the same concentration, it had no effect on GRF-induced GH secretion. d-Lys3-GHRP-6, a GHRP-6 antagonist, had no effect on GHRP-6 or L-692,429-induced GH secretion even at an i.v. dose of 2 mg/kg. These results indicate that L-692,429 and GHRP-6 stimulate GH release both in vitro and in vivo via a common receptor and signaling pathway which is different from that of substance P in spite of the fact that their effects are inhibited by a weak substance P antagonist. Journal of Endocrinology (1997) 152, 155–158

scholarly journals Pregnancy, but not dietary octanoic acid supplementation, stimulates the ghrelin-pituitary growth hormone axis in mice

2020 ◽  
Vol 245 (2) ◽  
pp. 327-342 ◽  
Author(s):  
Harleen Kaur ◽  
Beverly S Muhlhausler ◽  
Pamela Su-Lin Sim ◽  
Amanda J Page ◽  
Hui Li ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Octanoic Acid ◽  
Late Pregnancy ◽  
Acid Supplementation ◽  
Gh Secretion ◽  
Prohormone Convertase 1 ◽  
Total Ghrelin ◽  
Mrna And Protein Expression ◽  
Pregnant Mice ◽  
Acyl Ghrelin

Circulating growth hormone (GH) concentrations increase during pregnancy in mice and remain pituitary-derived. Whether abundance or activation of the GH secretagogue ghrelin increase during pregnancy, or in response to dietary octanoic acid supplementation, is unclear. We therefore measured circulating GH profiles in late pregnant C57BL/6J mice and in aged-matched non-pregnant females fed with standard laboratory chow supplemented with 5% octanoic or palmitic (control) acid (n = 4–13/group). Serum total and acyl-ghrelin concentrations, stomach and placenta ghrelin mRNA and protein expression, Pcsk1 (encoding prohormone convertase 1/3) and Mboat4 (membrane bound O-acyl transferase 4) mRNA were determined at zeitgeber (ZT) 13 and ZT23. Total and basal GH secretion were higher in late pregnant than non-pregnant mice (P < 0.001), regardless of diet. At ZT13, serum concentrations of total ghrelin (P = 0.004), but not acyl-ghrelin, and the density of ghrelin-positive cells in the gastric antrum (P = 0.019) were higher, and gastric Mboat4 and Pcsk1 mRNA expression were lower in pregnant than non-pregnant mice at ZT23. In the placenta, ghrelin protein was localised mostly to labyrinthine trophoblast cells. Serum acyl-, but not total, ghrelin was lower at mid-pregnancy than in non-pregnant mice, but not different at early or late pregnancy. In conclusion, dietary supplementation with 5% octanoic acid did not increase activation of ghrelin in female mice. Our results further suggest that increases in maternal GH secretion throughout murine pregnancy are not due to circulating acyl-ghrelin acting at the pituitary. Nevertheless, time-dependent increased circulating total ghrelin could potentially increase ghrelin action in tissues that express the acylating enzyme and receptor.

scholarly journals Effect of Synchronous Versus Sequential Regimens on the Pharmacokinetics and Biodistribution of Regorafenib with Irradiation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Tung-Hu Tsai ◽  
Yu-Jen Chen ◽  
Li-Ying Wang ◽  
Chen-Hsi Hsieh
Keyword(s):  
Stereotactic Body Radiation Therapy ◽  
In Vivo Studies ◽  
Control Group ◽  
High Dose ◽  
Dependent Manner ◽  
Hep G2 ◽  
Time Curve ◽  
Dose Dependent

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)regorafenib by 74% (p = 0.001) in the RT2 Gy × 3 fraction (f’x) group and by 69% (p = 0.001) in the RT9 Gy × 3 f’x group. The AUCregorafenib was increased by 182.8% (p = 0.011) in the sequential RT2Gy × 1 f’x group and by 213.2% (p = 0.016) in the sequential RT9Gy × 1 f’x group. Both concurrent regimens, RT2Gy × 3 f’x and RT9Gy × 3 f’x, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib × 3 d) group. The concurrent regimens, both RT2Gy × 3 f’x and RT9Gy × 3 f’x, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).

scholarly journals Effect of lemon peel flavonoids on anti-fatigue and anti-oxidation capacities of exhaustive exercise mice

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Guili Bao ◽  
Yinglong Zhang ◽  
Xiaoguang Yang
Keyword(s):  
Skeletal Muscle ◽  
Superoxide Dismutase ◽  
Manganese Superoxide Dismutase ◽  
Fatty Acid Content ◽  
Hepatic Tissue ◽  
Control Group ◽  
Dependent Manner ◽  
Lemon Peel ◽  
Tnf Α ◽  
Dose Dependent

AbstractIn this study, lemon peel flavonoids (LPF) were administered to investigate its effect on the anti-fatigue and antioxidant capacity of mice that undergo exercise until exhaustion. LPF (88.36 min in LPFH group mice) significantly increased the exhaustion swimming time compare to the untreated mice (40.36 min), increased the liver glycogen and free fatty acid content in mice and reduce lactic acid and BUN content in a dose-dependent manner. As the concentration of lemon peel flavonoids increased, the serum creatine kinase, aspartate aminotransferase, and alanine aminotransferase levels of mice gradually decreased. LPF increases superoxide dismutase (SOD) and catalase (CAT) levels in mice and reduces malondialdehyde levels in a dose-dependent manner. And LPF raises hepatic tissue SOD, CAT activities and reduces skeletal muscle tissue iNOS, TNF-α levels of mice compared to the control group. LPF also enhanced the expression of copper/zinc-superoxide dismutase (Cu/Zn-SOD), manganese-superoxide dismutase (Mn-SOD), and CAT mRNA in mouse liver tissue. LPF also enhanced the expression of alanine/serine/cysteine/threonine transporter 1 (ASCT1) mRNA and attenuate the expression of syncytin-1, inducible nitric oxide synthase (iNOS), and tumor necrosis factor (TNF)-α in mouse skeletal muscle. According to high-performance liquid chromatography (HPLC) analysis, it was found that LPF contains flavonoids such as rutin, astragalin, isomangiferin, naringin, and quercetin. Our experimental data show that LPF has good anti-fatigue effects and anti-oxidation ability. In summary, LPF has high prospects to be developed and added to nutritional supplements.

Toxicopathological effects of lambda-cyhalothrin in female rabbits (Oryctolagus cuniculus)

2010 ◽  
Vol 30 (7) ◽  
pp. 591-602 ◽  
Author(s):  
Abdul Basir ◽  
Ahrar Khan ◽  
Riaz Mustafa ◽  
Muhammad Zargham Khan ◽  
Farzana Rizvi ◽  
...  
Keyword(s):  
Blood Cell ◽  
Oryctolagus Cuniculus ◽  
Hemoglobin Concentration ◽  
Control Group ◽  
Mean Corpuscular Hemoglobin ◽  
Dependent Manner ◽  
Cell Counts ◽  
Lambda Cyhalothrin ◽  
Group A ◽  
Dose Dependent

The aim of this study was to investigate effects of lambda-cyhalothrin (LCT) on clinical, hematological, biochemical and pathological alterations in rabbits (Oryctolagus cuniculus). New Zealand white female rabbits (n = 24) of 4-5 months age having 997.92 ± 32.83 g weight were divided into four equal groups. Group A (control) received normal saline intraperitoneally (ip). Animals in groups B, C and D were treated with LCT 1.0, 4.0 and 8.0 mg/kg bw ip. Each group received seven consecutive doses at an interval of 48 hours. Blood and serum samples were collected at an interval of 96 hours. Blood analysis revealed a significant (p < 0.05) decrease in red blood cell and white blood cell counts, hemoglobin concentration and lymphocytes, while mean corpuscular hemoglobin concentration, mean corpuscular volume, neutrophils, monocytes and eosinophils were increased. Serum biochemical analysis revealed significant (p < 0.05) decrease in serum total proteins and serum albumin, while an increase was seen in serum alanine aminotransferase and aspartate aminotransferase activities compared with the control group. Serum globulin values varied non-significantly in all treatment groups as compared to control group. A dose-dependent increase in the incidence of micronucleated polychromatic erythrocyte was observed. All gross and histopathological lesions observed in LCT-treated rabbits were dose-dependent. Liver of the treated rabbits exhibited extensive perihepatitis, hyperplasia of bile duct, necrosis, hemorrhages and congestion. In lungs, there were hemorrhages, thickened alveolar walls, congestion, emphysema, collapsed alveoli and accumulation of extensive inflammatory cells. Kidneys were congested and hemorrhagic whereas renal parenchyma and stroma were normal. Microscopically, heart showed congestion of blood vessels and nuclear pyknosis, myodegeneration. It was concluded from the study that LCT produced toxicopathological alterations in rabbits in a dose-dependent manner. On the basis of the results, it can be suggested that overdosing of LCT be avoided while treating animals for ectoparasites.

Human MutT Homolog 1 (MTH1) Inhibitor Reduces the Biological Activity of Ovarian Carcinoma Cells

2022 ◽  
Vol 12 (5) ◽  
pp. 907-913
Author(s):  
Liyan Zhong ◽  
Yi Yi ◽  
Qian Liu ◽  
Yan Peng
Keyword(s):  
Biological Activity ◽  
Ovarian Carcinoma ◽  
Biological Activities ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Ovarian Carcinoma Cells ◽  
Proliferative Rate ◽  
Skov3 Cells ◽  
Significant Difference ◽  
Dose Dependent

This study intends to discuss the mechanism of MTH1 inhibitor (TH588) in the biological activity of ovarian carcinoma cells. A2780 and SKOV-3 cells were treated with different concentrations of TH588 and assigned into AT group (control), BT group (8 μmol/L TH588), CT group (16 μmol/L), DT group (32 μmol/L), ET group (64 μmol/L) and FT group (128 μmol/L) followed by measuring level of Bcl-2 and Bax by Western blot and PCR, and cell biological activities by MTT, FCM and Transwell chamber assay. The cell proliferative rate was not affected in AT group, but was lower in other groups in a reverse dose-dependent manner. There was significant difference on apoptotic rate and cell invasion among groups with increased apoptosis and reduce invasion after TH588 treatment. FT group showed lowest expression of Bcl-2 and Bax compared to other groups. In conclusion, the biological activity of A2780/SKOV3 cells could be reduced by MTH1 inhibitor which was probably through regulation of Bax and Bcl-2 expression.

Biological activity of partially purified low molecular weight luteinizing hormone binding inhibitor in porcine follicular fluids

1993 ◽  
Vol 128 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Nobuyoshi Kokawa ◽  
Mareo Yamoto ◽  
Kenichi Furukawa ◽  
Ryosuke Nakano
Keyword(s):  
Molecular Weight ◽  
Luteinizing Hormone ◽  
Competitive Inhibition ◽  
Biological Activities ◽  
Partial Purification ◽  
Low Molecular Weight ◽  
Dependent Manner ◽  
Hormone Binding ◽  
Dose Dependent ◽  
Follicular Fluids

We performed partial purification of low molecular weight luteinizing hormone binding inhibitor from porcine follicular fluids and examined its biological activities. Following ultrafiltration, gel filtration and anion exchange of the pooled porcine follicular fluids, low molecular weight fractions (500–10,000 MW) inhibited [125I]hLH binding to porcine granulosa cells in a dose-dependent manner. The binding inhibition kinetics study revealed that the luteinizing hormone binding inhibitor may indicate a non-competitive inhibition with [125I]hLH binding. In vitro bioassay using adult mouse testicular interstitial cells revealed that the partially purified luteinizing hormone binding inhibitor reduced ovine LH-stimulated testosterone and cAMP production in a dose-dependent manner, whereas the luteinizing hormone binding inhibitor did not affect basal production of testosterone and cAMP. The inhibitory activity was heat stable and did not disappear with activated charcoal adsorption. The results of the present study suggest that the luteinizing hormone binding inhibitor may play an important role as an ovarian non-steroidal regulator modulating the receptor binding of LH and LH-mediated steroidogenesis.

ATI-2341 Trifluoroacetic Acid (TFA) Promotes Menstrual Blood-Derived Mesenchymal Stem Cell Recruitment and Enhances Uterine Repair Through Gi Pathway in Asherman’s Syndrome

2022 ◽  
Vol 12 (3) ◽  
pp. 506-513
Author(s):  
Ying Lv ◽  
Liyan Ye ◽  
Xiujuan Zheng
Keyword(s):  
Menstrual Blood ◽  
Control Group ◽  
Dependent Manner ◽  
Asherman’S Syndrome ◽  
Expression Levels ◽  
Endometrial Cells ◽  
Injury Model ◽  
Recruitment Effect ◽  
Dose Dependent

This study aimed to explore the role of ATI-2341 in Asherman’s syndrome and its impact on menstrual blood-derived mesenchymal stem cells (MenSCs). Following establishment of endometrial injury model, MenSCs were extracted from rats and cultured. They were treated with ATI-2341 TFA at different concentrations (10 ng/mL, 50 ng/mL, 100 ng/mL) and MenSCs treated without ATI-2341 TFA were taken as controls. Flow cytometry was conducted to detect the cell cycle. MTT was carried out to evaluate proliferation of endometrial cells. The expression levels of MMP-9, TIMP-1, CK, and VIM were determined with staining used to reflect morphology of endometrium. Administration with ATI-2341 TFA resulted in decreased expression of MMP-9 and increased expression of TIMP-1 in a dose-dependent manner. Of note, the increase of ATI-2341 TFA concentration was accompanied with elevated cell proliferation rate, increased number of glands in the endometrium, and decreased fibrosis area. As treated with 100 ng/mL ATI-2341 TFA, the cells exhibited more glands than that under other concentrations with uniformly arranged glands and lowest expression levels of CK and VIM, control group had plenty of blue-stained collagen fibers in the intima and least amount of glands. ATI-2341 TFA 100 ng/mL induced endometrial epithelial recruitment effect on MenSCs and promoted endometrial repair more significantly than Gi-3 pathway agonists. Collectively, ATI-2341 TFA enhances MenSC recruitment and facilitates endometrial epithelial cells proliferation and the repair of uterine damage in Asherman’s syndrome through Gi pathway. These findings provide a\ novel insight into the MenSC-based treatment against Asherman’s syndrome and deserve further investigation.

Discovery of a Novel Small-Molecule Interleukin-6 Inhibitor through Virtual Screening Using Artificial Intelligence

2021 ◽  
Vol 18 ◽  
Author(s):  
Yoshiaki Sato ◽  
Ikuo Kashiwakura ◽  
Masaru Yamaguchi ◽  
Hironori Yoshino ◽  
Takeshi Tanaka ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Small Molecule ◽  
Interleukin 6 ◽  
Inflammatory Diseases ◽  
Biological Activities ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Cell Functions ◽  
Dependent Cell ◽  
Dose Dependent

Background: Interleukin-6 (IL-6) is a multifunctional cytokine involved in various cell functions and diseases. Thus far, several IL-6 inhibitors, such as, humanized monoclonal antibody have been used to block excessive IL-6 signaling causing autoimmune and inflammatory diseases. However, anti-IL-6 and anti-IL-6 receptor monoclonal antibodies have some clinical disadvantages, such as a high cost, unfavorable injection route, and tendency to mask infectious diseases. While a small-molecule IL-6 inhibitor would help mitigate these issues, none are currently available. Objective: The present study evaluated the biological activities of identified compounds on IL-6 stimulus. Methods: We virtually screened potential IL-6 binders from a compound library using INTerprotein’s Engine for New Drug Design (INTENDD®) followed by the identification of more potent IL-6 binders with artificial intelligence (AI)-guided INTENDD®. The biological activities of the identified compounds were assessed with the IL-6-dependent cell line 7TD1. Results: The compounds showed the suppression of IL-6-dependent cell growth in a dose-dependent manner. Furthermore, the identified compound inhibited expression of IL-6-induced phosphorylation of signal transducer and activator of transcription 3 in a dose-dependent manner. Conclusion: Our screening compound demonstrated an inhibitory effect on IL-6 stimulus. These findings may serve as a basis for the further development of small-molecule IL-6 inhibitors.

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